“Panspermia” Makes A Comeback: Did Life Begin On Mars?

In 1877, the Italian astronomer Giovani Schiaparelli conducted an observation of the surface of Mars, describing “canali” across the surface. The word “canali” actually means “channels,” but the word was incorrectly translated into English as “canals,” sparking what would become a fixation on the possibility of life on Mars. Those hopes were recently rekindled when NASA discovered water on Mars—but other clues tell us we could still be looking at the problem the long way. Is it possible that we have already discovered Martian life?

Recently, the idea that life on Earth existed elsewhere first has gained traction. The theory, called “panspermia” or “life everywhere,” became particularly popular during the 19th century because it explained some lingering gaps in Darwin’s concept of evolution. The evolution of complex creatures through the process of natural selection was believed to require at least hundreds of millions of years—a number that is difficult to reconcile with 19th-century estimates of the Earth’s age which was originally measured in the tens of millions. Panspermia solved that problem.

In the 20th century, when the age of Earth was no longer a barrier, the theory slipped away. At times, it was resurrected, but never really caught on. But in the last decade, panspermia has made a comeback among scientists in search of the origin of life. At very least, scientists have started to accept that the very early stages of life could have taken place outside of Earth. The formation of organics has always been an easy piece of the puzzle to solve, but getting from there to an actual organism is quite difficult.

That’s where Mars comes in.

In fact, the most crucial finding of the Mars Rover is likely not that water exists on the planet now, but that it once held water in the past. For those who subscribe to the theory of the RNA world, or the idea that the earliest life was composed of a strand of RNA, Mars was likely a better incubator for life than the Earth.

Steven Benner, the founder of the Westheimer Institute at the Foundation for Applied Molecular Evolution in Florida, has been attempting to find a pathway from simple organics to a simple organism of self-replicating RNA. That’s no easy feat, especially with the conditions on Earth. Mars likely had an abundance of borate, molybdate, and oxygen—key ingredients for facilitating RNA.

If life did arise on Mars, its travel to Earth is definitely within reason. Modern tests have shown that microbes can survive a journey on a meteorite—an enticing explanation for the lingering mystery of life.

What do you think? Have we been looking in the wrong place all along?

Source: NPR

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